The aim of this study is to clarify the difference of the principles of layout structure between the old Essex Design Guide and the new with the analysis of the respective backgrounds. The cul-de-sac in modern estate design was invented by Unwin (1863-1940) and Parker (1867-1947), and has been developed to the one in the old guide. The cul-de-sac in the old guide is used as a method to create a Townscape and to control car traffic. On the contrary, deformed grid was adopted by the new guide with the concepts of permeability and legibility. The deformed grid is used in the new guide from the point of view of the interrelationships between buildings, spaces and human activities.
